The present invention is directed to the problem of providing heart valves for transplantation. More particularly, the present invention is directed to the problem of providing a flow system to assist in transforming a heart valve that is based on a xenograft into an autograft.
There is at present a shortage in the supply of heart valves available for transplantation. Indeed, since 1984, allograft heart valve transplantation in the United States has increased to over 2,400 grafts per year. Because of this increased demand, particularly for pediatric cases, the utilization of cryopreseved heart valves is not limited by the supply of donated human hearts. There remains a need to address this supply problem.
One approach, with which this application is concerned, is to turn to tissue engineering to create a graft. Such a graft would be immunologically acceptable to the recipient and have long-term durability that exceeds presently available homograft or chemically-fixed valves. Furthermore, a low incidence of failure due to leaflet calcification or stiffening would be expected. Based on the extracellular matrix remaining after decellularization of a porcine aortic valve, the remnant scaffold would be recolonized with autogenous fibroblasts recovered from the skin of the intended recipient. Ideally, the repopulating cells could functionally replace the native cells that were removed to enhance the immunologic acceptability of the graft.
Such living heart valves could be tailored to the intended recipient. These living heart valves could replace the diseased and damaged valves with one indistinguishable from the patient's own tissue. These valves would be self-repairing, capable of growth and response with the patient. Despite being the graft of choice for repair of congenital malformations, allograft valves do not grow necessitating additional surgeries to implant larger valves as the heart size increases.